1. Field of the Invention
This invention relates to a method for the continuous production of ribbon cables with electrical conductors, which are arranged spaced apart from each other and parallel with respect to each other and are embedded in insulating material, wherein ribbon-shaped conductors are guided, spaced apart from each other, on one level, forming two surfaces, and the surfaces have insulating layers on the basis of thermoplastic materials, and the ribbon-shaped conductors are embedded between the insulating layers.
2. Discussion of Related Art
Ribbon cables are employed in great numbers in the electronic industry, computer industry and, for example, in connection with products where little space is available, such as in motor vehicles, or aircraft, for example. A conventional method is the production of ribbon cables by extrusion, wherein endless conductors are passed through a nozzle and are enclosed by the extruded molten plastic material. These ribbon cables are called flat extruded cables (FEC).
A further method is the production of ribbon cables by laminating them between two plastic films made of a thermally-stable thermoplastic material, wherein there is an adhesive layer between the two plastic films as the embedding layer, in which the conductors are embedded. These ribbon cables are also called flexible flat cables (FFC).
U.S. Pat. Nos. 5,917,154 and 3,833,443, PCT International Publications WO 87/06760 and WO 98/52199 and European Patent Reference EP 0 675 576, for example, in connection with teach the above explained prior art.
The ribbon cables must meet the requirements regarding temperature resistance, hydrolysis resistance, little shrinkage, easy processability, and simple production of contacts and connectors.
In connection with FFC ribbon cables, laminated with the use of an adhesive layer, the adhesive layer can be problematical, because it must be removed in the areas of contact points. The laminated films also have a tendency to become delaminated at high temperatures, such as can occur in the summer in the engine and the roof area of motor vehicles, for example.
With extruded FEC ribbon cables there is a tendency of the conductors to wander during production, so that inaccuracies in the cable guidance exist. Also, lower limits apply to the thickness of the extruded insulating layer, so that as a rule the FEC ribbon cables are thicker than the FFC ribbon cables produced by lamination.